Thank you for your clarification. See if I get this correct: So what I have is two accounts connected to the same machine, each connected with two VNC sessions (the 2D X server) and this is working fine as I can see the desktops. I have one 3D X server instance configured using xorg.conf, with 4 Nvidia GPUs and as far as I can tell from the document, this xorg.conf has been configured as headless.
My issue now, it seems, only one user is able to access the 3D X server properly. The other account, when running vglrun, will throw errors like [VGL] WARNING: The OpenGL rendering context obtained on X display [VGL] :0.3 is indirect, which may cause performance to suffer. [VGL] If :0.3 is a local X display, then the framebuffer device [VGL] permissions may be set incorrectly. I am just trying to get the two accounts to use the 3D X server, so I was wondering if the issue lies with my xorg.conf or somewhere else? Again, thank you for your replies. I am learning (albeit slowly). On Tue, Oct 10, 2017 at 3:14 PM DRC <[email protected]> wrote: > You are either still fundamentally misunderstanding how to configure a > VirtualGL server, or you are not describing your configuration properly. > "I have two VNC servers (from two different users) running on an > instance of X on :0" makes no sense. As I explained before, VNC is the > 2D X server, not the 3D X server. xorg.conf is used to configure the 3D > X server. In a normal VirtualGL environment, :0.0, :0.1, :0.2, etc. are > screens on the 3D X server, each assigned to a different GPU. In a > normal VirtualGL environment, :1.0, :2.0, :3.0, etc. are X proxy/2D X > server instances. > > On 10/9/17 9:09 PM, Jafaruddin Lie wrote: > > Thanks, DRC. > > I commented out the InputDevice(s) lines, now I have two VNC servers > > (from two different users) running on an instance of X on :0 (ps aux > > shows "X: 0") > > > > The first user to login via the job controller is allocated the first > > two graphic cards, and this user has no issue > > running vglrun glxgears (just to test). > > The second user is allocated the remaining graphic cards, and got this > > message: > > > > [VGL] WARNING: The OpenGL rendering context obtained on X display > > [VGL] :0.3 is indirect, which may cause performance to suffer. > > [VGL] If :0.3 is a local X display, then the framebuffer device > > [VGL] permissions may be set incorrectly. > > > > And this error from glxinfo: > > name of display: :2 > > X Error of failed request: GLXBadContext > > Major opcode of failed request: 152 (GLX) > > Minor opcode of failed request: 6 (X_GLXIsDirect) > > Serial number of failed request: 43 > > Current serial number in output stream: 43 > > > > That error persists with all the display number that I've tried (-d 0.0 > > to -d 0.3). > > Is there anything I am missing from my X configuration here?? > > > > On Tue, Oct 10, 2017 at 12:18 PM DRC <[email protected] > > <mailto:[email protected]>> wrote: > > > > You're missing the point. In a VirtualGL environment, there are two > X > > servers: > > > > -- The "3D X server" is a shared resource. It is used by multiple > users > > simultaneously in order to access the GPU, so it needs to remain > > running. It is only necessary to run one instance of the 3D X > server, > > although multiple GPUs can be assigned to different screens on that X > > server. This allows VirtualGL to address the GPUs separately, which > can > > be useful for load balancing (assigning different users to different > > GPUs) in large multi-user environments. > > > > -- The "2D X server" (X proxy) is per-user and can be > started/stopped as > > needed. TurboVNC is our recommended 2D X server/X proxy solution, > but > > VirtualGL can also be used with other X proxy solutions, including > > TigerVNC, Xpra, FreeNX, etc. The 2D X server receives and displays > the > > rendered 3D images from VirtualGL, as well as rendering the output of > > other (non-3D) X applications. It is this X server that you would > want > > to start/stop using your job controller. > > > > The basic purpose of VirtualGL is two-fold: > > > > (1) To allow multiple users to share a single GPU (via the 3D X > server > > instance) > > (2) To split 3D and 2D rendering to different X servers, so as to > enable > > hardware-accelerated OpenGL in an X proxy environment > > > > The relationship between the 3D X server and the 2D X server is thus > > one-to-many. Your test results made me remember a discussion about > this > > on the old virtualgl-users mailing list, and IIRC someone told me > that > > you have to disable the keyboard and mouse drivers in xorg.conf in > order > > for the 3D X server instance to be truly headless, i.e. for you to be > > able to disconnect it from the console without encountering errors. > Try > > commenting out > > > > InputDevice "Mouse0" "CorePointer" > > InputDevice "Keyboard0" "CoreKeyboard" > > > > and see if that changes the situation. If so, I'll add that to the > > how-to on VirtualGL.org. > > > > On 10/9/17 7:03 PM, Jafaruddin Lie wrote: > > > Thanks, our xorg.conf is already set to headless according to that > page. > > > Here's part of the section: > > > > > > Section "Screen" > > > Identifier "Screen0" > > > Device "Device0" > > > Monitor "Monitor0" > > > DefaultDepth 24 > > > Option "UseDisplayDevice" "none" > > > SubSection "Display" > > > Depth 24 > > > EndSubSection > > > EndSection > > > > > > Section "Device" > > > Identifier "Device0" > > > Driver "nvidia" > > > VendorName "NVIDIA Corporation" > > > BoardName "Tesla K80" > > > BusID "PCI:0:6:0" > > > EndSection > > > > > > Section "Monitor" > > > Identifier "Monitor0" > > > VendorName "Unknown" > > > ModelName "Unknown" > > > HorizSync 28.0 - 33.0 > > > VertRefresh 43.0 - 72.0 > > > Option "DPMS" > > > EndSection > > > > > > I'll test it with a single X instance and see how we go. > > > The reason we want to have multiple X is that these desktop > sessions are > > > started by a job controller (user will submit their request for a > > > desktop, which includes starting X). > > > We would like the X server to be killed whenever a user finishes > their > > > job, but one step at a time I suppose :) > > > > > > > > > On Tue, Oct 10, 2017 at 5:12 AM DRC <[email protected] <mailto: > [email protected]> > > > <mailto:[email protected] <mailto:[email protected]>>> wrote: > > > > > > Yes, it is possible. You don't actually even need multiple X > servers > > > for multiple users to use VirtualGL at the same time. > Multiple users > > > can share the same GPU using VirtualGL. That is one of its > purposes. > > > In order to use VirtualGL with multiple GPUs, generally the > easiest way > > > to do it is to configure a single X server with multiple > screens, so GPU > > > 0 would be accessible by setting VGL_DISPLAY=:0.0 and GPU 1 > would be > > > accessible by setting VGL_DISPLAY=:0.1, etc. The reason why > you are > > > getting the pixel readback error is because, unless the X > server is > > > headless, it has to be attached to the physical display in > order for > > > pixel readback to work. The only way to use VirtualGL with > multiple X > > > servers (:0.0, :1.0, etc.) is if one or more of them is > configured to be > > > headless. (https://virtualgl.org/Documentation/HeadlessNV > explains how > > > to configure a headless X server with an nVidia GPU.) > > > > > > On 10/9/17 5:35 AM, Jafaruddin Lie wrote: > > > > Hi all > > > > Simple question is if it is possible, on a single machine > with multiple > > > > GPUs, running different X servers on those GPUs, for > multiple users to > > > > use vglrun at the same time? > > > > This is our current setup: > > > > > > > > 1 machine with 4 Nvidia K80 cards (latest drivers), running > CentOS 7, > > > > VirtualGL 2.5.2, TightVNC, and Mate Desktop. > > > > > > > > We have 2 xorg.conf (2 cards configured on each xorg.conf), > and > > > > currently we are testing whether we can bring up 2 desktop > sessions via VNC. > > > > The desktop loads, and we can see two different X servers > running on > > > > those 4 cards and the VNC servers running on different > displays. > > > > > > > > The issue is with VirtualGL. The first user can do startx > and run vglrun > > > > glxgears, this will work fine. > > > > When the second user startx, the first user's vglrun session > will be > > > > terminated with this error: > > > > > > > > [VGL] ERROR: OpenGL error 0x0502 > > > > [VGL] ERROR: in readpixels--- > > > > [VGL] 439: Could not read pixels > > > > > > > > The first user can run vglrun again once the second user > stops their X > > > > session. > > > > My understanding is that with our setup, this should be > do-able, right? > > > > > > > > Thanks. > > > > > > -- > > > You received this message because you are subscribed to a > topic in > > > the Google Groups "VirtualGL User Discussion/Support" group. > > > To unsubscribe from this topic, visit > > > > https://groups.google.com/d/topic/virtualgl-users/5B331QalCaI/unsubscribe. > > > To unsubscribe from this group and all its topics, send an > email to > > > [email protected] > > <mailto:virtualgl-users%[email protected]> > > > <mailto:virtualgl-users%[email protected] > > <mailto:virtualgl-users%[email protected]>>. > > > To view this discussion on the web visit > > > > https://groups.google.com/d/msgid/virtualgl-users/e38fd010-f8e2-7faf-7e0b-2e3f68317985%40virtualgl.org > . > > > For more options, visit https://groups.google.com/d/optout. > > > > > > -- > > > You received this message because you are subscribed to the Google > > > Groups "VirtualGL User Discussion/Support" group. > > > To unsubscribe from this group and stop receiving emails from it, > send > > > an email to [email protected] > > <mailto:virtualgl-users%[email protected]> > > > <mailto:[email protected] > > <mailto:virtualgl-users%[email protected]>>. > > > To view this discussion on the web visit > > > > https://groups.google.com/d/msgid/virtualgl-users/CAOunvuMFtgSfjQf-TnmMMs1n5xOfUk520%2B2S0WgV6ipi-BEk-w%40mail.gmail.com > > > < > https://groups.google.com/d/msgid/virtualgl-users/CAOunvuMFtgSfjQf-TnmMMs1n5xOfUk520%2B2S0WgV6ipi-BEk-w%40mail.gmail.com?utm_medium=email&utm_source=footer > >. > > > For more options, visit https://groups.google.com/d/optout. > > > > -- > > You received this message because you are subscribed to a topic in > > the Google Groups "VirtualGL User Discussion/Support" group. > > To unsubscribe from this topic, visit > > > https://groups.google.com/d/topic/virtualgl-users/5B331QalCaI/unsubscribe. > > To unsubscribe from this group and all its topics, send an email to > > [email protected] > > <mailto:virtualgl-users%[email protected]>. > > To view this discussion on the web visit > > > https://groups.google.com/d/msgid/virtualgl-users/f34cbec1-b777-1970-86a2-f140907904eb%40virtualgl.org > . > > For more options, visit https://groups.google.com/d/optout. > > > > -- > > You received this message because you are subscribed to the Google > > Groups "VirtualGL User Discussion/Support" group. > > To unsubscribe from this group and stop receiving emails from it, send > > an email to [email protected] > > <mailto:[email protected]>. > > To view this discussion on the web visit > > > https://groups.google.com/d/msgid/virtualgl-users/CAOunvuPjSqe9k8SJWE_yF3tP8yXM%3DvC2eidvmJbXMhVruuzFuA%40mail.gmail.com > > < > https://groups.google.com/d/msgid/virtualgl-users/CAOunvuPjSqe9k8SJWE_yF3tP8yXM%3DvC2eidvmJbXMhVruuzFuA%40mail.gmail.com?utm_medium=email&utm_source=footer > >. > > For more options, visit https://groups.google.com/d/optout. > > -- > You received this message because you are subscribed to a topic in the > Google Groups "VirtualGL User Discussion/Support" group. > To unsubscribe from this topic, visit > https://groups.google.com/d/topic/virtualgl-users/5B331QalCaI/unsubscribe. > To unsubscribe from this group and all its topics, send an email to > [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/virtualgl-users/41e4806e-dc81-afda-95d3-4c3054090a35%40virtualgl.org > . > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "VirtualGL User Discussion/Support" group. 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